POM-V Prescription Required

Subestin 25 microgram/ml Oral Solution for Horses

Active ingredient: Clenbuterol Hydrochloride

Form

Liquid

Species

Horses

Manufacturer

Floris Holding B.V.

VMD MA No.

56190/5003

What it's used for

Treatment of respiratory disease in horses where it is considered that airway obstruction due to bronchospasm and/or accumulation of mucus is a contributin...

Full indications, dosage and side effects ↓

View official SPC (PDF)

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Paying less for Clenbuterol Hydrochloride

1

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They must provide one on request. Under the CMA Order the fee is capped at £21 from 2027.
2

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The CMA found online pharmacies 50–60% cheaper than practice dispensing on common medicines — typically £200–£300 a year.

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Prescription required

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Clinical information

Subestin 25 microgram/ml Oral Solution for Horses — SPC Details

Source: VMD Summary of Product Characteristics (SPC). Last updated 26 Mar 2026.

Treatment of respiratory disease in horses where it is considered that airway
obstruction due to bronchospasm and/or accumulation of mucus is a contributing
factor, and improved mucociliary clearance is desirable.
To be used alone or as adjuvant therapy.

Oral use
The veterinary medicinal product should be administered twice a day with
approximately 12 hours (minimum 8 hours) in between according to the following
dosage:
Administer 0.8 micrograms clenbuterol hydrochloride per kilo body weight (i.e. 0.7
micrograms clenbuterol per kg bodyweight), corresponding to 4 ml oral solution / 125
kg body weight, twice daily.
The duration of the treatment is a maximum of ten consecutive days.
The product is administered orally, through or over food.
This veterinary medicinal product is intended for individual treatment.

Do not use in cases of hypersensitivity to the active substance or any of the
excipients.
Do not use in horses with known cardiac disease.
For use during pregnancy or lactation see section 4.7.

Revised: April 2025
AN: 04090/2024Page 2 of 6

Clenbuterol may cause side effects such as sweating (mainly neck region), muscle
tremor, tachycardia, slight hypotension, restlessness or lethargy. These are typical
for β-agonists and occur rarely.
The frequency of adverse reactions is defined using the following convention:
- very common (more than 1 in 10 animals treated displaying adverse reaction(s))
- common (more than 1 but less than 10 animals in 100 animals treated)
- uncommon (more than 1 but less than 10 animals in 1,000 animals treated)
- rare (more than 1 but less than 10 animals in 10,000 animals treated)
- very rare (less than 1 animal in 10,000 animals treated, including isolated reports).

Revised: April 2025
AN: 04090/2024Page 3 of 6

None

Special precautions for use in animals
In cases accompanied by bacterial infection the administration of antimicrobial
agents is recommended.
In case of glaucoma the product must only be used after a careful risk-benefit
assessment.
Special precautions should be taken in case of halothane anaesthesia, since the
heart function can show increased sensitivity to catecholamines.
Special precautions to be taken by the person administering the veterinary medicinal
product to animals
This veterinary medicinal product contains clenbuterol, a beta-agonist, which may
cause adverse effects such as increased heart rate.
Dermal exposure and accidental ingestion, including hand-to-mouth contact should be
avoided. When using this product do not eat, drink or smoke to avoid accidental intake
of the product.
To avoid accidental ingestion by or exposure to a child, do not leave the filled syringe
unattended and close the bottle immediately and properly after use.
In case of accidental ingestion, seek medical advice immediately and show the
package leaflet or the label to the physician. Wash hands after use.
This product may cause embryotoxicity. Pregnant women should take care when
handling the product. Wear gloves to avoid skin contact.
This product may cause hypersensitivity reactions. People with known hypersensitivity
to any of the excipients (parabens, polyethylene glycol and/or triethanolamine)
avoid exposure to the product. In case of hypersensitivity reactions or if irritation
persists, seek medical advice and show the package leaflet or label to the physician.
This product may be irritating to the skin and/or eyes. Avoid skin and/or eye contact.
In case of accidental skin contact, wash skin thoroughly. In case of accidental eye
contact, flush thoroughly with clean water.

Effects including side effects may be enhanced with simultaneous use with
glucocorticoids, ß2-sympathomimetics, anticholinergics and methylxanthines.
The veterinary medicinal product should not be used concomitantly with other
sympathomimetics or vasodilators.
In animals treated with clenbuterol disturbances of the heart rhythm can be expected
upon anesthesia.
Simultaneous administration of narcotics containing halogens (isoflurane,
methoxyflurane) increases the risk of ventricular arrhythmias.
During the use of both local and general anaesthetics one cannot exclude a further
vascular dilatation and fall of blood pressure, particularly if used in combination with
atropine.
Increased risk of arrhythmia with simultaneous administration of digitalis glycosides.
The veterinary medicinal product can reduce or neutralise the effects of
prostaglandin F2α and oxytocin on the uterus.
Clenbuterol hydrochloride is a
β-blockers.

Do not store above 30 °C.

Meat and offal: 28 days
Not authorised for use in animals producing milk for human consumption.
5.

This information is sourced from the official Summary of Product Characteristics (SPC) published by the Veterinary Medicines Directorate (VMD). It is provided for informational purposes only and does not replace professional veterinary advice. Always consult your vet before administering any medication.